not able to implement jwt token using django

[rohit.a...@gmail.com]

class Login(APIView):

    SECRET =" demo"

    def post(self, request, *args, **kwargs):

        import ipdb;ipdb.set_trace()

        username = request.POST.get('username')

        password = request.POST.get('password')

        user = Person.objects.get(username=username, password=password)

        if user:

            payload = {

                'id': user.pk,

                'username': user.username,

                'staff': user.email,

                'exp': datetime.utcnow()

            }

            token = {'token': jwt.encode(payload, self.SECRET)}

            return HttpResponse(

              json.dumps(token),

              content_type="application/json"

            )

        else:

            return HttpResponse(

              json.dumps({'Error': "Invalid credentials"}),

error: type error json not serializable